Vehicle power transmission with service brakes

ABSTRACT

Power transmission in which the input rotor of a hydrodynamic torque-transmitting unit and a rotatable transmission input are selectively clutched and unclutched to control power flow through the unit. Controls associated with a gear selector mechanism for forward and reverse gearing effect the momentary disconnection of the input rotor and the transmission input when shifting gears. Disc brakes selectively engageable with the differential input provide vehicle service brakes. The housing of the torquetransmitting unit is rigidly connected to the transmission input by deforming a portion of the housing into appropriate openings formed in the transmission input.

United States Patent Hause [4 1 June 20, 1972 [54] VEHICLE POWERTRANSMISSION 2.3.3.226 8/1950 ask ..192/4 A X WITH SERVICE BRAKES l l1963 estmont.... ....l92/4 C X 1,835,412 12/1931 Livingood.......74/710.5 X [72] Inventor: Gilbert K. Hnuse, Bloomfield Hills, Mich.2,477,065 7/ 1949 Kvert et al.... 192/4 C X Assign: General Mom's Co onDetroit, 3,405,786 10/1968 Goode ..l88/264 E Mlch PrimaryExaminer-Benjamin W. Wyche [22] Filed: Nov. 10, 1970 Attorney-W. E.Finken, A. M. l-leiter and Charles R. White [21] Appl. No.: 88,457 IRelated U.S. Application pm 1 ABSTRACT Power transmission in which theinput rotor of a hydrodynam- [62] g g gg z March 1969 ictorque-transmitting unit and a rotatable transmission input areselectively clutched and unclutched to control power flow through theunit. Controls associated with a gear selector [52] U.S. Cl "7417102358,74/41 15, 18888/2762Z5, mechanism for forward and reverse gearing effectthe momen 1 [218 X l l E tary disconnection of the input rotor and thetransmission [51] m Fwd 67/00 input when shifting gears. Disc brakesselectively engageable [58] Field Of Search 192/4 A, 4 C, 4, 9;74/411.5, i h differential input provide vehicle Service brakes. The74/7105, 714, 695; 188/264 E, 72.5, 218 X housing of thetorque-transmitting unit is rigidly connected to the transmission inputby deforming a portion of the housing [56] References Cited intoappropriate openings formed in the transmission input.

UNITED STATES PATENTS 8 Claims, 1 Drawing Figure 2,647,597 8/1953 Keese..192/4 A 7 a! as i, I U 25! I] a 4:7 1 J s 1: 9 M r g MASTER -CYLINDERPATENTEDJum me m EozjU III v @522 nu mm RN Q1 kw 6 \1 R \1 N w Q1 ,mlIII w aw. m NM m m% mm N f R s I z k a 3 RE WW 1 I I i Q .1 N q,

. m Q mm mm 0 Q AT TORNEY VEHICLE POWER TRANSMISSION WITH SERVICE BRAKESThis is a division of application Ser. No. 805,745, filed Mar. 10, 1969now US. Pat. 3,590,966.

This invention relates to power transmissions and more particularly to atransmission featuring a new and improved connection between thetransmission input and a hydrodynamic unit housing, unique forward andreverse gearing driven by the unit and controls therefor, and anadvanced transmission braking system and a clutch and controls forselectively coupling and uncoupling the hydrodynamic unit rotor and thetransmission input.

In low-power-to-weight vehicles, such as the small economy typepassenger car, multi-stepped manual transmissions are generally employedto provide a range of output torques needed for efficient vehicleoperation. Due to the cost, complexity and space requirements, automatictorque converter transmissions generally have not been employed in suchvehicles.

This invention provides a highly efficient torque convertertransmission, which is inexpensive, uncomplicated and sufficiently smallto be effectively employed in the low-power-toweight vehicles mentionedabove. Although this invention is primarily for smaller vehicles asmentioned above, it can be employed in larger vehicles such as thestandard sixpassenger car.

The cost of this transmission is materially reduced by utilizing a newand improved connection between the flywheel and converter housing.Furthermore, simplified fonvard and reverse gearing is provided andthere are new and improved controls for eliminating power flow throughthe converter when the transmission gearing is conditioned for neutral.In this invention, forward and reverse transmission gears mesh directlywith the differential input gear, thereby providing a reduction intransmission size and weight. Disc brakes selectively engageable withopposing sides of the differential input gear provide new and improvedvehicle service brakes. In this invention the converter pump isselectively connected to the flywheel by improved clutch and controls.for forward and reverse drives.

An object of this invention is to provide a new and improvedtransmission featuring selectively operable forward or reverse gearingmeshing directly with the differential input gear and in which brakemeans are selectively engageable with the sides of the differentialinput gear to provide vehicle service braking.

Another object of this invention is to provide a transmission having ahydrodynamic unit and a new and improved connection between a rotatablecomponent of the unit, such as a hydrodynamic unit rotor.

Another object of this invention is to provide a new and improvedconnection between an annular transmission input and a metallic torqueconverter housing in which a portion of the housing is deformed into anannular groove and spaced openings to rigidly connect these parts in anassembly.

Another object of this invention is to provide a transmission includinga hydrodynamic unit having an input rotor selectively connected to thetransmission input by a new and improved clutching mechanism andcontrols so that the unit can transmit input torque therethrough.

Another object of this invention is to provide a new and improved torqueconverter transmission having a converter pump selectively connectedwith an input member by new and improved clutch and controls and inwhich forward and reverse gearing, selectively clutched to a converterdriven shaft, is directly connected to drive a differential input gear.

These and other objects of the invention will become more apparent fromthe following detailed description and from the drawing in which:

The FIG. is a side view partly in section of a torque convertertransmission and controls thereof.

As shown in the FIG., engine crank shaft 1, journaled in bearings 3 isdrivingly connected to a flywheel 5 located in case 7. The flywheel hasan annular rim 9 with an outwardly facing circular groove 11 machinedtherein and a series of LII spaced holes 13. The holes are drilledradially inwardly from the bottom of the groove toward the rotationalaxis of the flywheel 5 and a connected torque converter 15. The torqueconverter has a metallic shell-like housing 17, which has an annularside that fits over the rim of the flywheel. The annular portion of theside of the housing which extends over the groove 11 and radial holes 13is deformed into the grooves and holes to rigidly assemble the housingto the flywheel.

This connection may be accomplished by utilizing an electromagneticforming process. The housing is slipped on the flywheel and held'inplace by a fixture and then placed inside an electromagnetic formingcoil. Upon discharge of sufficient electrical energy through the coil,from a capacitor bank for example, the portion of the housing alignedwith the groove and holes is swaged simultaneously into the groove andholes by magnetic forces emanating from the coil to rigidly connect theparts. The annular seal 18 disposed between the flywheel and the housing17 makes this assembly fluid-tight. If desired, the assembly can be madeemploying a mechanical rolling operation with the holes staked fortorsional rigidity.

The torque converter has a pump 19, a turbine 21 and a stator 23 bladedin a conventional manner for the circulation of oil supplied to theconverter by a supply passage, not shown. A one-way brake connects thestator to a ground sleeve 24.

A clutch unit, which is preferably operated by engine oil, is

employed to selectively connect or disconnect the flywheel and the pump;this unit comprises an annular, longitudinally movable friction plate 25which has spaced tabs or teeth on the inner diameter which fit intocorresponding spaced and longitudinally extending slots 29 formed in theouter shell of the pump thereby providing a spline-like connection.There is also an annular piston 31 disposed in the converter housinghaving an .inner annular shoulder with a seal 33 molded thereon. Thisseal slidably mounts the piston on the inner cylindrical shoulder of thehousing 17 as shown. The piston also has an outer annular shoulder 34and annular seal 35 which slidable contact an annular internal portionof the housing to provide a chamber 37 between the end of housing 17-and piston 31. This chamber receives a pressure oil which ef-.

fects displacement of the piston so that the radially extending annularapply surface 38 of the piston will contact the friction plate 25 andmove itinto frictional engagement with the transverse end portion of theflywheel to drivingly connect the flywheel and pump. when chamber 37 isopen to exhaust, converter pressure provides the releasing force forpiston 31 and the clutch 25. As shown the FIG. the outer end ofthepiston has extending tangs or fingers 39, which slidably engage withsplines on the outer periphery of the flywheel. The piston only movesabout 0.015 inch between full apply and full release and is alwaysguided. The piston and housing have a similar radius of curvature toprovide a compact arrangement of parts. The housing 17 further has acylindrical sleeve 42 that extends away form the torque converter and isoperatively connected to the drive gear of fluid pump 44. Because themetal in the converter housing 17 extends into the axial holes in theflywheel, there is sufficient torsional rigidity to permit the engineand flywheel to drive the pump through the hous- Chamber 37 ishydraulically connected by a passage in the housing to an annular groove40 formed in a support sleeve 41, that supports rotatable'housing 17 andrigidly connects the ground sleeve to case 7. Annular groove 40 isconnected by a suitable passage 43 to a control valve 45, which will belater described. The turbine 21 has a hub journaled in the flywheel andis drivingly connected by splines 47 to a power transmitting shaft 49.This shaft is coaxial with the flywheel and torque converter and extendsfrom the torque converter through forward and reverse drive gears 53 and55 respectively located adjacent to one another and rotatably mounted onthe shaft. The shaft terminates in an end extension having spacedflanges 59 arranged to slidably receive a pin 61 therebetween secured toa crank member 63 which is supported in case 7 for turning with respectto axis 64. This crank member is turned by link 65 operatively securedto a conventional shift lever,- not shown. The shaft 49 carries astepped tooth dog clutch element 67 that is fixed to the shaft and isaccommodated by recess 69 formed between the gears 53 and 55. Thesegears are formed with internal clutching teeth 71 and 73 respectivelywhich are drivingly engageable with the stepped tooth dog clutch elementto connect the shaft 49 to either gear 53 or 55. In the position shownin the drawing, the dog clutch'element is in the neutral position and nopower can flow from the shaft to either gear.

The shaft 49 can be selectively connected to either gear 53 or 55 byappropriate axial movement of the shaft from the illustrated position inresponse to actuation of the shift lever and the correspondinglongitudinal movement of connected link 65 and rotation of crank 63. Asshown, the shaft carries a spring biased ball detent 75, whose ballmembers fit into anyone of the three side-by-side spaced grooves 77 toreleasably hold the shaft in an adjusted position. When the shaft 49 ismoved in either direction from its neutral position, illustrated in thedrawing, the teeth of the dog clutch element engage the appropriateclutching teeth of the selected gear 53 or 55 to thereby drivinglyconnect the shaft 49 with the selected gear.

Gear 53, providing a forward drive gear, meshes with gear 79 of adifferential drive 81, which is the subject of US. Pat. No. 3,520,2l3issued July 14, 1970 to Gilbert K. Hause and Clifford C. Wrigley andthis differential is only briefly described here.

Thegear 55 with an idler not shown, which in turn meshes withdifferential input gear 79 to provide a reverse drive. As shown, gear 79has transverse openings into which the inner ends of a pair ofaxleshafts 83 and 85 are rotatably joumaled. These shafts extendlongitudinally as does shaft 49 and have meshing spur gears 87 and 89 toprovide for differential speeds of the drive wheels when the vehicleusing this transmission negotiates a turn. To provide a compact powerpackage, axle shaft 85 is disposed through engine cam shaft 91 which isdriven by timing gear 93.

In this invention disc brakes are employed on opposite sides of the gear79 to provide vehicle service brakes. As shown, each brake assemblycomprises a brake shoe 95, hydraulically actuated piston 97 and spring99. Each shoe comprises a friction liner secured to a plate movablymounted in fixed caliper 100. The spring 99 is disposed at the rear ofeach piston, mounted in a bore in the caliper, provides a low force tolightly engage the shoe with the friction surface of gear 79 to therebyprovide a mechanism for automatically adjusting the brakes as they wear.The parasitical drag of the lining on the friction surface of the gearis sufficiently low so that it can be disregarded. The brakes areoperated in a lubricant for improved cooling. As diagrammaticallyillustrated, the pistons are hydraulically connected to a mastercylinder 101 so that the-brakes are applied when the brake pedal 103 isdepressed and so that they are released when the brake pedal isreleased.

The control valve 45 has a valve element 105 shiftable to direct fluidto and away from the piston chamber 37. As shown, the valve element hasa flanged operator end portion which slidably receives the extension 106of crank 63. In the neutral position shown, the valve element blocks thesupply of fluid from the pump 44 fed to the valve through passage 107.With no pressure in chamber 37 the clutch plate will be disengaged byconverter supply pressure. In neutral, both the converter and gearclutches are disengaged to provide a no-torque neutral.

in operation, forward drive is selected by moving link 65 to the rightthereby turning crank 63 on pivot 64 clockwise. Crank pin 61 willride-upwardly between flanges 59 and also push shaft 49 in towardthecrank shaft with splines 47 permitting this movement.

The dog clutch element 67 engages clutching teeth 71 to lock the forwardgear 53 to the shaft 49. At the same time, the valve element is shiftedto a forward drive position with the center land blocking exhaust 109and the passage 43 open to the passage 107. Fluid pressure is admittedto chamber 37 and the clutch is applied to connect the pump to theflywheel. Under these conditions the torque converter is operative totransmit and multiply torque to shaft 49. Power flows through shaft 49through the forward drive gear 53 to differential gear.

79 which runs partially submerged in oil. Power then flows to the axleshafts 83 and 85. Reverse is selected by pushing link 65 toward theconverter to turn the crank counterclockwise with respect to pivot 64.The crank slides shaft 49 to the right so that dog clutch element 67will drivingly engage the reverse gear 55 and also move the valveelement through a neutral, exhaust position to a third position in whichchamber 37 is again charged with fluid under pressure. This momentaryinterruption of converter operation when shifting between forward andreverse causes shaft 49 and the gear 79 to decelerate and prevents asudden torque reversal -on the differential input gear. 7

Springs 99 apply forces only sufficient to maintain the shoes in lightcontact with the lubricated annular friction surfaces of the largetransfer or difl'erential gear 79 and with out removing the oil filmthereon. This provides for improved braking since the shoes will effecthigh capacity braking action as soon as pedal 103 is depressed. Thelubricant in the housing is at least sufficient to cover the frictionsurfaces of the brake shoes.

It will be appreciated thatapplicant has provided an improved powerpackage with an advanced torque converter design, improved transfergearing and also advanced braking. as well as the other advancements andimprovements set forth above. Although a particular embodiment of thisinvention is shown and described, it will be understood that this ismerely illustrative of the invention and other modifications can bereadily made. My invention is defined in the claims which follow:

1 claim:

1. A power transmission comprising transmission input means, powertransmitting means drivingly connected tosaid input means, forward drivegear means and reverse drive gear means rotatably mounted adjacent toone'another on a portion of said power transmitting means, clutch meansoperatively connected to said power transmitting means for selectivelyconnecting either said forward drive gear means or said reverse drivegear means to said power transmitting means, a differential having aninput gear operatively connected to said forward and reverse drive gearmeans and having first and second output members extending in oppositedirections, said input gear having an annular friction surfacedirectl'yon at least one side face thereof, brake means for comprisingfriction means frictionally engaging said frictional surface of saiddifferential input gear, and motor means for effecting the selectivebraking engagement of said friction means with said frictional surfaceto retard rotation of said first and second output members.

2. The transmission of claim 1, said power transmitting means comprisinga hydrodynamic unit and a drive shaft extending axially from said unit,spline means drivingly connecting said hydrodynamic unit and said driveshaft and permitting the limited axial movement of said drive shaftrelative to said hydrodynamic unit, said clutch means being within saidforward and reverse drive gear means and actuator means for axiallyshifting said drive shaft axially to selectively clutch shaft to saidforward or said reverse gear means.

3. In a unitary power package, rotatable input drive means operativelyconnected to an engine, rotatable input gear means operatively connectedto said input drive means for transmitting engine power therefrom, saidinput gear means having an annular arrangement of gear teeth, rotatableoutput drive means, rotatable output gear means drivingly connected tosaid output drive means, said output gear means having an annulararrangement of gear teeth which mesh with said gear teeth of said inputgear means, said output gear means having an integral hub portiondisposed radially inwardly of said gear teeth thereon, an annularfriction surface provided directly on each side of said hub portion,abrake shoe on each side of said output gear means positioned for theselective engagement said with each annular friction surface, andactuating means for exerting an apply force on each of said brake shoesurging said brake shoes toward one another for effecting the fullfrictional engagement of each brake shoe with the cooperating frictionsurface on said hub portion of said output gear means to retard rotationof said output gear means and said output drive means.

4. The invention defined in claim 3 and a housing for said input andoutput gear means, said housing having fluid lubricant therein with alevel covering the portion of said annular friction surfaces engaged bysaid brake shoes for lubricating and cooling said friction surfaces andbrake shoes.

5. The invention defined in claim 4, said brake actuating meanscomprising a master cylinder for effecting the engagement of each brakeshoe, each of said brake shoes being provided with a spring whichapplies a force just sufficient to cause said shoes to contact thefriction surfaces of said output gear means without braking effort sothere is a minimum movement of said brake shoes on brake engagement inresponse to actuation of said master cylinder.

6. The invention defined in claim 3, a selectively engageable inputclutch driven by an engine, a torque converter driven by the inputclutch, said input gear means comprising forward and reverse gearingdriven by said torque converter for driving said output gear means, saidoutput gear means having a large diameter to provide a large reductiondrive ratio, and said annular friction surfaces on said output gearmeans being disposed adjacent to the outer perimeter of said output gearmeans for providing a large brake capacity.

7. The invention defined in claim 6 and said output gear means has alarge sleeve hub with a differential Therein, said output drive meansbeing a pair of axle shafts rotatably mounted in said hub.

8. The invention defined in claim 3 and an engine having a crank shaftaxially aligned and drivingly connected to said input drive means, saidengine also having a tubular cam shaft and a portion of said outputdrive means extending through said tubular cam shaft.

* 1 i II t

1. A power transmission comprising transmission input means, powertransmitting means drivingly connected to said input means, forwarddrive gear means and reverse drive gear means rotatably mounted adjacentto one another on a portion of said power transmitting means, clutchmeans operatively connected to said power transmitting means forselectively connecting either said forward drive gear means or saidreverse drive gear means to said power transmitting means, adifferential having an input gear operatively connected to said forwardand reverse drive gear means and having first and second output membersextending in opposite directions, said input gear having an annularfriction surface directly on at least one side face thereof, brake meansfor comprising friction means frictionally engaging said frictionalsurface of said differential input gear, and motor means for effectingthe selective braking engagement of said friction means with saidfrictional surface to retard rotation of said first and second outputmembers.
 2. The transmission of claim 1, said power transmitting meanscomprising a hydrodynamic unit and a drive shaft extending axially fromsaid unit, spline means drivingly connecting said hydrodynamic unit andsaid drive shaft and permitting the limited axial movement of said driveshaft relative to said hydrodynamic unit, said clutch means being withinsaid forward and reverse drive gear means and actuator means for axiallyshifting said drive shaft axially to selectively clutch said shaft tosaid forward or said reverse gear means.
 3. In a unitary power package,rotatable input drive means operatively connected to an engine,rotatable input gear means operatively connected to said input drivemeans for transmitting engine power therefrom, said input gear meanshaving an annular arrangement of gear teeth, rotatable output drivemeans, rotatable output gear means drivingly connected to said outputdrive means, said output gear means having an annular arrangement ofgear teeth which mesh with said gear teeth of said input gear means,said output gear means having an integral hub portion disposed radiallyinwardly of said gear teeth thereon, an annular friction surfaceprovided directly on each side of said hub portion, a brake shoe on eachside of said output gear means positioned for the selective engagementwith each annular friction surface, and actuating means for exerting anapply force on each of said brake shoes urging said brake shoes towardone another for effecting the full frictional engagement of each brakeshoe with the cooperating friction surface on said hub portion of saidoutput gear means to retard rotation of said output gear means and saidoutput drive means.
 4. The invention defined in claim 3 and a housingfor said input and output gear means, said housing having fluidlubricant therein with a level covering the portion of said annularfriction surfaces engaged by said brake shoes for lubricating andcooling said friction surfaces and brake shoes.
 5. The invention definedin claim 4, said brake actuating means comprising a master cylinder foreffecting the engagement of each brake shoe, each of said brake shoesbeing provided with a spring which applies a force just sufficient tocause said shoes to contact the friction surfaces of said output gearmeans without braking effort so there is a minimum movement of saidbrake shoes on brake engagement in response to actuation of said mastercylinder.
 6. The invention defined in claim 3, a selectively engageableinput clutch driven by an engine, a torque converter driven by the inputclutch, said input gear means comprising forward and reverse gearingdriven by said torque converter for driving said output gear means, saidoutput gear means having a large diameter to provide a large reductiondrive ratio, and said annular friction surfaces on said output gearmeans being disposed adjacent to the outer perimeter of said output gearmeans for providing a large bRake capacity.
 7. The invention defined inclaim 6 and said output gear means has a large sleeve hub with adifferential therein said output drive means being a pair of axle shaftsrotatably mounted in said hub.
 8. The invention defined in claim 3 andan engine having a crank shaft axially aligned and drivingly connectedto said input drive means, said engine also having a tubular cam shaftand a portion of said output drive means extending through said tubularcam shaft.